At present, there are two forms of grouper culture: net box culture and pond culture. Here is what I have carefully organized for you to take a look at the feeding methods of grouper.
Grouper Rearing Methods
When selecting, attention must be paid to the quality of the fish. The fish should be selected for breeding if they are strong, vigorous, free from disease and scale damage, and have a good glossy skin color.
Adult grouper farming is mainly done in two ways: net box farming and pond farming, with net box farming being more common. Grouper net box culture is an intensive aquaculture, high stocking density, easy to manage, high production efficiency, so the development is very fast. In the introduction of adult fish culture technology, net box culture is the main, pond culture and indoor cement pond culture can refer to net box culture.
Farming conditions
The environment of the aquaculture sea area should have the following conditions: good wind conditions, waves are not too big, not attacked by typhoons; sandy bottom, gravelly bottom, reef bottom is good, the depth of water should be more than 4 meters at low tide; the tide is smooth, the flow rate is moderate, the flow rate in the net box to keep in the 0.20 m / s ~ 0.75 m / s good; minimum water temperature in winter is not more than 0.75 m / s. The net box can also be used as an aquatic environment. The minimum water temperature in winter should not be lower than 15℃, and the number of days of water temperature from 22℃ to 28℃ should not be less than 200 days; the water quality should be fresh and clean, and the adaptive range of grouper to salinity should be wide, and the fish can survive between 11?-41?, and the optimal salinity should be 25-32?, pH=7-9, and the dissolved oxygen should be more than 5mg/liter; the water should not be contaminated with industrial and agricultural waste water and urban sewage, and the season of storm should not be characterized by a large amount of inflow of freshwater, and the salinity should not be lower than 16, and the transparency should be 1.5 meters. Not less than 16, transparency of more than 1.5 meters; good traffic conditions, live fish transportation, feed supply is convenient.
At present, the grouper nursery has not yet reached the requirement of productivity, so the cultured fish are still raised as fry by the juvenile fish caught in the natural sea area. The cultured grouper larvae are better caught by hand fishing. When selecting, attention must be paid to the quality of the fish. Fish that are strong, vigorous, free of disease and scale damage, and with good glossy skin color should be selected for culture.
Stocking specifications and density
Stocking density has a great relationship with the current speed of the aquaculture sea area, the smooth flow of the sea area can be larger, and vice versa to be less. Generally a 3?3?3 (m) net box, stocking species specifications in the 50 grams / tail of each box can be put
2500 tail, specifications in the 150 grams / tail of each box of about 1000 tail. That is to say a 3?3?3 (meters) net box culture yield of about 200 kilograms is more appropriate. The stocking density of grouper in seawater net box culture is 60 tails/cubic meter to 70 tails/cubic meter under the condition of 25℃ water temperature. In production practice, about 500 adult fish were reared in a 3-meter?3-meter?3-meter net box. The results showed that the growth of grouper was faster at stocking densities of 15 and 30 fish/m3, and the growth rate was similar to that of the former when the stocking density was increased to 60 fish/m3, with no obvious difference. However, when the stocking density was increased to 120 tails/m3, the tail weight gain decreased, the feed coefficient increased greatly, and the survival rate decreased significantly. It was proved that the stocking density of 60 tails/m3 for adult fish was more appropriate. Zhejiang Xiangshan Harbor sea area net box culture red spotted grouper, tail weight 100g ~ 150g stocking density of 90 tails / square meter ~ 70 tails square meter is appropriate.
Feed and baiting technology
Grouper is a carnivorous fish, and the main feed used for feeding is small mixed fish with high freshness. Generally, according to the size of grouper, use the fish cutter to cut the small mixed fish into suitable size and then feed. The feeding coefficient fluctuates from 5 to 12 depending on the type of fish to be fed; the feeding coefficient of blue round fish as feed is lower, while the feeding coefficient of eye fish is higher. With the rapid development of grouper net box aquaculture industry, the supply of feed fish is getting tighter and tighter, and it is imperative to promote the feeding of grouper with artificial feed. Practice shows that grouper has high requirements on the palatability of feeds such as softness, hardness, color and taste, and prefers soft particles, light color and bright feeds, and spitting phenomenon if the particles are too hard, and its adaptability to soft particles feed is obviously better than hard particles feed. There is a long adaptation process from feeding small mixed fish to feeding artificial compound feed, and feeding compound feed should be domesticated before feeding. The appropriate content of crude protein in the artificial compound feed for red grouper is 40%-50%; the appropriate content of protein in the compound feed for green grouper is 51%-55%, and the appropriate content of fat is about 9.87%. If the fat content in the feed is increased appropriately, more protein can be used for the growth of the fish body without being consumed as an energy substance, which can play the role of saving protein and improving the utilization rate of feed protein. Wet mass feeds made from fishmeal as the main protein source were fed to salmon grouper minnows and fry, and the best growth was achieved when the protein content was 40% to 50% and 54%, respectively. Salmon grouper were fed dry compound feeds with fishmeal and casein as the proteogens at an optimum protein content of 50%. The amino acid composition of grouper muscle has little interspecies variation, and the composition pattern of 10 essential amino acids is lysine: leucine: arginine: valine: threonine: isoleucine: phenylalanine: methionine: histidine: tryptophan=9.8:9.1:7.7:5.2:5.0:4.9:4.8:3.1:2.6:1.0. This amino acid composition pattern can provide a reference for the configuration of compound feeds for grouper. This amino acid composition pattern can be used as a reference for grouper compound feed configuration. The electrophysiological thresholds of alanine stimulation in grouper (Epinephelus erythropolis) and green grouper (Epinephelus erythropolis) were 10 moles/liter to 9.9 moles/liter and 10 moles/liter to 9.6 moles/liter, respectively, which were significantly lower than those in other fish species. This may be related to the fact that they live among the bottom rocky reefs, the visual function is degraded while the olfactory function is relatively developed. It provides a better prospect for the study of olfactory food attractants for grouper. Grouper have special requirements on feed particle size. When feeding adult fish, the particle size of pellet feed should not be less than 6 mm, and the particles are too small for high appetite
Feeding technology has a greater impact on the effect of grouper aquaculture. Under the environmental condition of 25℃ water temperature, the digestion speed of grouper is about 20 hours to 24 hours. Therefore, in the South China Sea waters from May to October, grouper are fed once a day, usually at 9:00 a.m. to 11:00 a.m. In November to December and March to April, grouper are fed once every two days, and in winter, when the seawater temperature drops to less than 20 ℃, the grouper are fed once every three days to four days. The amount of feeding each time is about 3% to 5% of the body weight, the amount of feeding is larger when the water temperature is suitable, and the amount of feeding is reduced when the water temperature is lower or too high. In production, generally depending on the feeding status of the grouper to determine the feeding amount, to the extent that the appetite is weakened. The general principle of feeding is that the small tidal current is slow and clear, and the water temperature is suitable for more feeding, but less feeding. The daily baiting amount is generally 8% of the weight of the fish, and each time when feeding, it should be put into a small amount, slowly sprinkled in batches, and then sprinkled the next batch of feeds after snatching the previous batch of feeds until it is full and does not snatch the feeds, and the feeds must not be dumped into the nets at one time, so as not to cause waste of feeds and pollution of the environment, and the grouper will never eat the food that sinks to the bottom. Since the grouper is swallowing the food, the individual size of the bait should be smaller than the caliber of the fish. Feeding should also pay attention to the principles of fixed quality, fixed quantity and fixed time. Pond culture should also pay attention to set up a feed table, feeding at regular intervals, in order to improve the utilization of feed and easy to clean up the residue, to maintain good water quality.
Grade feeding
Fish stocking should be stocked according to the size of the fish body grade feeding. Theoretically analyzed, the smaller the individual difference the better, but the actual operation is more difficult to do. Because of the size of the fish body grade difference is small, feeding evenly, is conducive to growth.
Daily management
Choose a reasonable density of nets and rafts to prevent the occurrence of hypoxia. In addition to baiting in the aquaculture process, it is necessary to frequently observe and check the growth, feeding, activity and body color of the fish, but also frequently check whether there is any damage to the net box, the number of attached organisms, and regularly remove the attached fouling organisms on the net box in order to maintain a smooth flow of water in and out of the net box. Fouling organisms can be removed by using preventive agents, mechanical cleaning and chemical treatment, and matching with natural enemies that feed the fouling organisms. Regular sieving to maintain the same size of grouper in the same net box. Because fish have the effect of big fish overpowering the growth of small fish and the phenomenon of self-cannibalization when they are hungry, they should be sifted regularly to make the size of grouper in the net box uniform. Mix a small amount of snapper and omnivorous fish. In this way, one can remove the bottom of the residual food and net box on the defacement of organisms; secondly, because the snappers grab food strong, can stimulate the appetite of grouper; thirdly, can make full use of the water body space and feed resources, improve the breeding efficiency. Reinforcement of iron anchors and cables, regular checking of the breakage of the nets to ensure safe production. Especially before the arrival of typhoons, it is more important to strengthen the defense, strengthen the anti-wind and wave measures, and do a good job of safety to ensure production safety. Regularly monitor the water quality and protect the breeding environment. Monitor the aquaculture water according to the first category of seawater quality standard issued by the state, which is conducive to the normal growth of grouper and meat quality, and prevent accidents caused by deterioration of water quality.
Current status of grouper breeding
Grouper is a warm-water offshore demersal valuable seawater fish with high economic value. There are 10 genera and more than 100 species of grouper in the whole world, of which the genus Grouper is the largest genus with more than 60 species, and more than 30 species have been recorded in the offshore of China. At present, there are more than 10 kinds of grouper that have been artificially nursed and cultured, which are mainly: oblique banded grouper (green spot), red spotted grouper (red spot), saddle banded grouper (gentian grouper), brown spotted grouper (tiger spot), clouded grouper (oil spot), brown grouper (false oil spot), green grouper (earth spot), jeweled grouper (sesame spot), seven-banded grouper, and gill gill spine perch (eastern star spot). There are also "green dragon spot" (Department of oblique banded grouper female X gentian grouper male) and "pearl gentian (Department of brown spot grouper female X gentian grouper male) and other grouper interspecies hybrids.
In Fujian Province, grouper are mainly cultured, followed by red-spotted grouper, clouded grouper and green grouper, etc. In addition, a small amount of saddle grouper is also cultured. In addition, a small amount of grouper farming is also done for saddle banded grouper, brown spotted grouper, brown grouper, and "green dragon spot" and "pearl gentian". 11,200 tons of grouper were farmed in Fujian Province in 2010, second only to Hainan Province (57,000 tons) and Taiwan Province (27,000 tons). In 2010, the production of grouper culture in Fujian Province was 11.2 thousand tons, only following Hainan Province (57 thousand tons) and Taiwan Province (27 thousand tons). Zhangpu has the largest production of grouper culture in Fujian Province, which is 2043 tons, followed by Dongshan, Jiaocheng, etc.
Grouper culture production in Fujian Province is the largest in Fujian Province, which is 2043 tons.
Grouper are both marine and freshwater fish.